Question

I created below code in a Objective C program to get the size of a file in a directory and I must do it in C without using any Objective-C methods. This works fine and gives the correct size when checking it with small size files. But when it comes to large files (tested with 7GB file) this size variable returns the size of the file as 0. Can anyone help me to solve this issue?

//filePath is a string parameter which takes the path of the file
    FILE *fp=nil;
    const char  *filePathInToChar = [filePath UTF8String];
    fp = fopen(filePathInToChar, "rb");
    fseek(fp, 0, SEEK_END);
    long size = ftell(fp);

Answer 1

Your problem is that ftell returns the current position in the filestream as long int which on a 32bit system has usually a maximum value of 2^31 – or 2GB in other words.

You can use stat (so you don’t actually need to open and close the file):

#include <sys/stat.h>

struct stat buf;
stat(filePathInToChar, &buf);
off_t size = buf.st_size;

off_t should be long long which is usually 64bit.